One of the first to go was the controversial but popular technique of forcing a suspect to partake in a highly incriminating crime scene 're-enactment', often in front of photographers.

Re-enactments were widely stopped for a while, but now Thai newspapers are once again peppered with police photos of nervous suspects posing with guns or pointing to blood stains at crime scenes.

Few are ever told their rights, observers warn, adding they believe that beatings to force confessions have yet to be fully stamped out in some provinces.

'In practical terms there has been very little change in the way things work,' said Sarawut Pratoomraj, campaign co-ordinator for the Committee of Human Rights Organisations.

'The poor still effectively have no rights but the constitution was supposed to make all Thai people equal under the law. Our society and government must be stronger. The police issue shows we have a long way to go.' Without a meaningful charter, other activists fear there will be no change to the 'round up the usual suspects' approach in rural Thailand, where crimes involving the rich and powerful are often swept under the carpet or blamed on someone far less influential.

Even the most high-profile crimes remain showcases of many of the hard-boiled procedures the police hold dear.

As the political and international pressure mounts to solve the killing of Australian investigative accountant Michael Wansley three weeks ago, Interior Minister Sanan Kachornprasart has said the suspected gunman would be taken dead if he did not surrender.

'Wanted Dead or Alive' reward posters for Pachit Kasensanduang have started appearing across southern Thailand.

'We do mean wanted dead or alive in terms of the new constitution, of course,' said investigation head Police General Prasarn Wongyai. 'Police are allowed to shoot to defend themselves. The constitution is important to us in our work.' As investigations centre on the wealthy businessman believed to have ordered the killing, police have already paraded the man they claim organised the hit.

Boonphan Sutthiwiriwan denied any role yet provocatively said Thais had to stand up for their 'economic sovereignty' as foreigners exploited the economic crisis.

Another man, who rode the motorcycle that carried the gunman, has already pleaded guilty and has been sentenced to life imprisonment.

Senior police sources conceded that much work was still needed to fully implement the charter but urged patience.

A powerful Human Rights Commission - still on the drawing board - would help 'concentrate' the minds of officers in the field.

'We are actively studying how to change,' one senior officer involved with the charter said. 'The problem is that there are pockets of our force that are laws unto themselves, through years of corruption and political connections. This cannot be changed overnight. It means changing a whole culture.'